SNOMED concepts make up a significant percentage of the UMLS Metathesaurus. Hence, the correctness of their semantic type (ST) assignments contributes significantly to the overall correctness of ST assignments throughout the UMLS. Two kinds of semantic concept groupings within SNOMED are employed to automatically check for potentially inconsistent ST assignments, based on their collective sets of assignments. The first kind of concept grouping, called a semantic uniformity group (SUG), is based on concepts' properties and hierarchical configurations. The second kind constitutes intersections of groupings of the first kind ("overlapping SUG" (OSUG)). The methodology is applied to SNOMED's Specimen hierarchy, where 448 concepts residing in 40 SUGs are analyzed. A hypothesis concerning the fact that OSUGs can be stronger indicators of inconsistencies than SUGs is considered. The results show that our methodology can be effective in finding ST assignment problems and thus can augment the suite of techniques available for managing the enormous amount of such assignments.